Russia-Ukraine updates: US sanctions Russian military shipbuilder, diamond miner

Fierce fighting between Russian and Ukrainian forces continued in Mariupol on Wednesday morning, with the Ukrainian government warning that as many as 100,000 civilians -- or 22% of the besieged port city's original population -- remain trapped there.

One Mariupol resident, Natalia, who managed to escape with her elderly parents and four cats, told ABC News her home had no electricity or heat and that she would have to scavenge for food and other supplies under Russian bombardment. She recalled seeing bodies strewn in the streets because residents had no choice but to leave them there.

"We understood anytime we might be killed by the next bomb," Natalia said during an interview Tuesday.

Pro-Russia separatist forces from the self-declared Donetsk People's Republic in Ukraine's disputed Donbas region said Wednesday that 562 civilians, including 110 children, were evacuated from encircled Mariupol to the occupied town of Bezymenne in the past 24 hours. A total of 4,621 civilians were evacuated from Mariupol between March 5 and March 23, according to the separatist forces.

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Ukrainian forces strike back as Russia steps up siege of MariupolJames Longman reports from Lviv with the latest on the war in Ukraine.

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Russia and Ukraine have exchanged prisoners twice since the start of the war, according to Russian Ministry of Foreign Affairs spokesperson Maria Zakharova.

"Two prisoner exchanges have been completed between Russia and Ukraine," Zakharova said in a statement Wednesday.

Russia's ambassador to Poland, Sergey Andreev, said Wednesday that he has received a note from the Polish Ministry of Foreign Affairs demanding the expulsion of 45 Russian diplomats on charges of espionage.

The diplomats must leave Poland within five days, according to Andreev.

The news came after a spokesperson for Poland's Internal Security Agency announced on Polish television that authorities had compiled a list of 45 Russian diplomats in the country who were suspected of spying.

Kremlin spokesman Dmitry Peskov warned Wednesday that Poland's "actions will not be left without retaliation."

Russian shelling hit two residential areas of Kyiv on Tuesday night, according to the city administration.

A shopping center and two private houses were damaged in the Sviatoshynskyi district of the Ukrainian capital, but no one was injured and the fires have been extinguished, officials said.

Several private houses and high-rise buildings were on fire in the Shevchenkivskyi district, where four people were injured. Rescuers and medics were still on the scene Wednesday, and the extent of the damage was under assessment, according to officials.

A 35-hour curfew across Kyiv ended Wednesday morning.

-ABC News' Julia Drozd